Cement structures, particularly those using reinforced concrete, suffer degradation over time and with use. Cracks often develop and even portions of the cement may dislodge.
The problem becomes particularly acute in regions which include salt as an environmental ingredient. This occurs, of course in localities near the ocean which receive salt directly form the water spray and the like. Furthermore, the salting of roads in the northern portions of this country during winter have an especial destructive effect upon cement structures.
The repair of cement damage by the environment and use generally commences with the removal of the remaining surface layers of concrete. This cleans out degraded or dislodged cement, much like drilling a decayed tooth. Replacing the removed cement with new concrete precludes the further and dangerous degradation of the cement structure.
The removal of cement has often entailed the use of jack hammers generally operating under pneumatic pressure. This type of equipment has proven very slow, requires a large number of employee hours, and thus entails a very substantial ezpense to a structure's owner. It can also create microcracks in the structure.
A more recent type of device employs a strong stream of water, under high pressure, to remove the superficial cement. Typically, a nozzle moves across a boom positioned over a cement floor, roadway, or the like. The boom, in turn, connects to a tractor which moves in the direction generally perpendicular to that in which the nozzle travels. The coordinated motions of the nozzle on the boom moving in a first direction and the tractor holding the boom in a perpendicular direction permits the coverage of a large area of cement floor or roadway with a minimal number of employees. It also produces a smoother surface which admits to a more uniform layer of new cement and thus a stronger resulting structure. The Atlas-Copco Company in Sweden has produced equipment of this type.
However, the hydraulic demolition equipment utilizing a nozzle traveling on a boom attached to a tractor has a limited utility. It only operates upon the upward-facing surface upon which the tractor may sit. This limits its use to cement floors, roadways, aprons, and the like.
However, many cement structures have downwardly facing surfaces as well. This occurs, of course, in buildings. The ceiling surface may also undergo degradation, especially in structures such as parking lots or other areas which suffer heavy wear from vehicles. The search for equipment to effectuate the surface demoltion of cement on ceiling surfaces accordingly continues.
One of the primary objects of the present invention is to provide novel apparatus for removing concrete from a ceiling surface.
A more particular object of the present invention is to provide a novel apparatus for removing concrete from a ceiling surface for repair of the ceiling and which employs a mobile support truck adapted for movement along a floor surface or the like. The truck carries a pair of telescoping upstanding support arms which support a transverse boom so as to enable selective orientation of the boom relative to a ceiling surface. A carriage is reciprocally moveable along the boom and carries a lance having a high pressure fluid discharge nozzle thereon operative to discharge high-pressure fluid, such as water, against the ceiling surface as the nozzle and truck undergo predetermined movement relative to the ceiling surface.
A feature of the ceiling concrete removing apparatus in accordance with the present invention lies in the provision of control means at opposite ends of the boom which are operative in response to traverse of the carriage to effect automatic reversal and reciprocating movement of the carriage.
Further objects, advantages and features of the invention, together with the organization and manner of operation thereof, will become apparent from the following description of the invention when taken in conjunction with the accompanying drawings wherein like reference numerals designate like elements throughout the several views.